diff --git a/channels/shangwutong/internal/swt/client.go b/channels/shangwutong/internal/swt/client.go
index 3228bd58..3294c28b 100644
--- a/channels/shangwutong/internal/swt/client.go
+++ b/channels/shangwutong/internal/swt/client.go
@@ -198,13 +198,14 @@ func (c *Client) sendHTML(ctx context.Context, session Session, sid, content, op
 		return SendResult{}, &Error{Operation: operation, Code: "network_error", Retryable: true, Err: err}
 	}
 	status := strings.TrimSpace(response.Header.Get("r"))
-	if !strings.EqualFold(status, "ok") {
-		if protocolError := strings.TrimSpace(response.Header.Get("error")); protocolError != "" {
+	successful := strings.EqualFold(status, "ok")
+	if !successful {
+		if protocolError := strings.TrimSpace(response.Header.Get("error")); protocolError != "" && !strings.EqualFold(protocolError, "ok") {
 			status = protocolError
 		}
 	}
 	result := SendResult{Status: status, Body: body}
-	if strings.EqualFold(status, "ok") {
+	if successful {
 		return result, nil
 	}
 	code := normalizeCode(status)
diff --git a/channels/shangwutong/internal/swt/client_test.go b/channels/shangwutong/internal/swt/client_test.go
index 02e8a851..59986224 100644
--- a/channels/shangwutong/internal/swt/client_test.go
+++ b/channels/shangwutong/internal/swt/client_test.go
@@ -77,6 +77,8 @@ func TestClientSendTextClassifiesProtocolStatus(t *testing.T) {
 		{name: "explicit failure", status: "failed", wantCode: "failed"},
 		{name: "error header", protocolError: "state err", wantCode: "state_err"},
 		{name: "retryable error", protocolError: "server err", wantCode: "server_err", wantRetryable: true},
+		{name: "error cannot override failure", status: "failed", protocolError: "ok", wantCode: "failed"},
+		{name: "error cannot supply success", protocolError: "ok", wantCode: "missing_status"},
 		{name: "missing status", wantCode: "missing_status"},
 	}
 	for _, test := range tests {